They carried out 19 robberies in north and east London between April and May.

Mensah was jailed for 13 years, Osondu for 11 years and Ali for eight years at Wood Green Crown Court on Tuesday, Scotland Yard said.

One of their victims was left with horrific burns on his face, which left him like a “zombie”.

Miracle Osondu (Metropolitan Police/PA)

He said in a statement: “The initial injuries were that my skin was burnt all over, even in my mouth and on my tongue.

“Even after I gave them what was in my pockets, they kept pouring acid over me, just because they could.

“When I looked in the mirror and saw my injuries for the first time, I felt like I had become a zombie in just two hours.”

He was blinded in one eye and added that “anything that relied on my eyesight has been robbed from me”.

The muggers started their spree by robbing a taxi driver in Enfield with a knife and threatening to stab him on April 26.

A knife seized from Miracle Osondu (Metropolitan Police/PA)

In another incident on May 11, they arranged to meet a 40-year-old man in Barnet, pretending they were going to buy a phone he had advertised on Gumtree.

They sprayed ammonia in the victim’s face and stole the phone, leaving him with serious eye injuries, impaired vision and psychologically traumatised.

The trio carried out a similar attack the next day, dousing a 49-year-old man with acid after luring him to a street in Barking, saying they were going to sell him a phone.

They sprayed acid in his face, stole cash and his wallet before returning and spraying him again.

The victim sustained life-changing injuries, including losing most of his sight in one eye which meant he had to leave his job.

Mohammed Ali (Metropolitan Police/PA)

Mensah, of Wood Green, north London, was given an extended sentence which included a jail term of 13 years and a period on extended licence of 17 years.

Osondu, of Beckton, east London, was given an extended sentence which included a jail term of 11 years and a period on extended licence of 15 years.

Ali, of Ilford, east London, was given an extended sentence which included a jail term of eight years and a period on extended licence of 12 years.

They were arrested together in a taxi on their way to commit another robbery and had a bottle of acid, 22cm blade, £2,000 cash and balaclavas with them.

Detective Constable James Rush described them as “dangerous individuals” and said their crimes were “truly shocking”

“These males appeared to feel no guilt over their actions, using strong acids, alkalis, and knives, to rob and maim their victims without a second thought for the impact the injuries they inflicted would have,” he added.

A Gumtree spokeswoman said: “We take the safety of our users extremely seriously and we are pleased to see the perpetrators of these appalling crimes brought to justice.

“Our dedicated Safety Team works closely with the police to share information and support their investigations. We list prominent safety advice for users on every ad on our website, a summary of which can be found at help.gumtree.com.”